package com.kai.service.util;

import org.jetbrains.annotations.NotNull;
import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.stereotype.Component;

import java.util.Map;

@Component
public class SpringContextUtil implements ApplicationContextAware {

    /** 应用上下文全局锁 */
    private static final Object lock = new Object();

    private static ApplicationContext applicationContext; // Spring应用上下文环境

    /**
     * 实现了ApplicationContextAware 接口，必须实现该方法；
     * 通过传递applicationContext参数初始化成员变量applicationContext
     */
    @Override
    public void setApplicationContext(@NotNull ApplicationContext applicationContext) throws BeansException {
        if (checkNull(SpringContextUtil.applicationContext)) {
            synchronized (lock) {
                if (checkNull(SpringContextUtil.applicationContext)) {
                    SpringContextUtil.applicationContext = applicationContext;
                }
            }
        }
    }

    public static ApplicationContext getApplicationContext() {
        return applicationContext;
    }

    @SuppressWarnings("unchecked")
    public static <T> T getBean(String name) throws BeansException {
        return (T) applicationContext.getBean(name);
    }

    public static <T> T getBean(Class<T> clazz) throws BeansException {
        return applicationContext.getBean(clazz);
    }

    public static <T> Map<String,T> getBeansOfType(Class<T> clazz)throws BeansException{
        return applicationContext.getBeansOfType(clazz);
    }

    private boolean checkNull(ApplicationContext applicationContext) {
        return applicationContext == null;
    }
}